When Microsoft CEO Satya Nadella extolled his company's love for Linux -- an open source operating system it previously opposed -- it would be natural to assume that commitment came with a few caveats. On Monday, the company doubled down on its love for open source in one of the most surprising ways possible.

SQL Server, one of the most popular pieces of database server software, and a crown jewel of Microsoft's enterprise software empire, is coming to Linux.

It's a shocking move from Microsoft, after Nadella first professed love for Linux in late 2014. The company plans to have SQL Server available for Linux by the middle of next year, Microsoft Executive Vice President Scott Guthrie said in a blog post. The goal is to provide a consistent data platform across both Windows and Linux.

SQL Server for Linux will carry key features that users expect from the server software, including a Stretch Database service that lets administrators send data from on-premises servers to the Azure cloud for storage while keeping it accessible for applications that query a particular database table.

"This is an enormously important decision for Microsoft, allowing it to offer its well-known and trusted database to an expanded set of customers," IDC analyst Al Gillen said. "By taking this key product to Linux, Microsoft is proving its commitment to being a cross-platform solution provider."

Starting on Monday, the company is rolling out a private beta test of the software with the core relational database components of SQL Server. It's unclear when the public will be able to try SQL Server on Linux.

All of this comes as Microsoft has sent out its first release candidate beta for SQL Server 2016 on Windows, too.